Hmm, the thing is I have Vista on my machine too and it works fine. I'm guessing there's something left over from an old public beta which it doesn't like.
To be completely sure it's not an old install, you could try:
- Uninstall any versions of Construct you already have (including 0.83.2)
- Make sure the key HKEY_CURRENT_USER\Software\Construct is deleted
- In your Application Data directory (eg. C:\Documents and Settings\Username\Application Data\, hidden by default) delete both the 'Construct' and 'Scirra' folders.
- Reinstall 0.83.2.
If that still doesn't work, I will poke around with Construct on Vista and try to break it